JP2001146339A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device constituted so that jammed paper can easily be confirmed and jamming is restored. SOLUTION: In this image forming device for transferring a toner image formed on an image carrier to a sheet and fixing the image so as to form the image, a part of a guide member forming a sheet carrying passage is made of the transparent resin and formed freely to be opened and closed. This image forming device has a roller type fixing device provided with a first rotatable roller having a heating source and a second roller to be rotated while being brought in contact with the first roller and the guide member forming the sheet carrying passage at an upper position of the second roller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copier, a printer, and a printer having an improved structure so that when a sheet made of plain paper or the like used for image formation is jammed (paper jam), the treatment can be easily performed. Alternatively, the present invention relates to an image forming apparatus such as a multifunction peripheral in which a facsimile function is incorporated.

[0002]

2. Description of the Related Art A conveyance path for a sheet on which an image is to be formed is provided, an appropriate number of conveyance means including a pair of rollers are provided on the conveyance path, and a detection means for detecting a conveyed sheet is provided. Image forming apparatuses such as copiers and printers configured to warn the operator of the occurrence of a jam based on the sheet detection information of the detection means are well known.

[0003] A configuration is known in which the transfer electrode and the separation electrode are unitized and provided rotatably.

The above-described image forming apparatus is generally a roller-type fixing device mainly including a rotatable heating roller having a heating source, and a pressure roller which rotates while being in pressure contact with the heating roller. The image forming apparatus includes a fixing device having a pressure bonding mechanism capable of pressing the pressure roller against the heating roller and separating the pressure roller from the heating roller.

[0005] In these configurations, the place where the jam occurs can be immediately confirmed, so that quick processing is possible. Further, since a large space can be created by unitization, the removal processing is easy, and furthermore, a compact and efficient fixing is achieved. This is a useful configuration that can be performed.

[0006]

However, the transport path is generally constituted by a plurality of guide members. For example, when the transport path is required to be longer than the length of the sheet to be used in the transport direction depending on the location. Occurs.

Further, such a transport path is often formed in a tunnel shape covering four surroundings. If there are a plurality of such transport paths, and if they are provided close to each other, In particular, there is a problem that even if the sheet detecting means is appropriately arranged, it takes time to specify the location.

Further, in a configuration in which the transfer / separation unit is rotated to open the sheet conveyance path in the transfer / separation area, the transfer / separation unit is rotated to the maximum in order to make as much space as possible. Due to the configuration, the photoconductor provided on the surface of the image carrier deteriorates depending on the number of times of processing, and if the image forming process is performed immediately after the jam processing, an image with fog may be produced,
Further, there is a problem that the fear of damaging the surface of the image carrier increases.

This is particularly likely to occur in a configuration in which the width direction of the image carrier is front and the front side is open.

Further, the conventional roller-type fixing device has only a mere fixing function, and requires a complicated and large releasing mechanism for separating the pressure roller from the heating roller during the jam processing. It did not contribute much to the downsizing of the device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a main object of the present invention is to provide an image forming apparatus having a configuration capable of easily confirming and processing jammed paper during jam processing.

Another object of the present invention is to provide an image forming apparatus which is configured to minimize the adverse effect on the image carrier due to the opening of the transfer separation area at the time of jam processing or the like.

It is still another object of the present invention to provide an image forming apparatus having a roller-type fixing device capable of separating rollers by a simple operation at the time of a jam clearance and having a function other than a fixing function.

[0014]

The object of the present invention can be achieved by the following constitution.

(1) In an image forming apparatus in which a toner image formed on an image carrier is transferred onto a sheet and fixed to form an image, a part of a guide member forming a sheet conveying path is formed of a transparent resin. An image forming apparatus, which is provided so as to be openable and closable.

(2) The first toner image formed on the image carrier is transferred onto one surface of a sheet conveyed along the first conveyance path,
After fixing, the sheet is turned upside down via a second conveyance path, and then re-sent to the first conveyance path to transfer and fix a second toner image on the other surface of the sheet to form an image. In the image forming apparatus to be manufactured, a part of the guide member constituting the first transport path or the second transport path is made of a transparent resin, and is arranged to be openable and closable.

(3) The image forming apparatus according to (1) or (2), wherein the opening and closing is a rotation about one end as a fulcrum.

(4) A part of the first transport path is the second transport path.
A part of the guide member forming the conveyance path cooperates with a part of the guide member forming the first conveyance path, and a part of the second conveyance path cooperates with a part of the guide member forming the first conveyance path. The image forming apparatus according to (2), wherein:

(5) At least one of the guide members forming the second conveyance path is provided integrally with an opening / closing door provided on a side surface of the apparatus main body. The image forming apparatus according to any one of 4).

(6) In an image forming apparatus having a transfer / separation unit provided opposite to the image carrier, the transfer / separation unit is provided rotatably with one end as a fulcrum, and at least two-stage rotation. An image forming apparatus characterized in that a corner is obtained.

(7) The image forming apparatus according to (6), wherein the transfer separation unit is exposed by opening an opening / closing door provided on a side surface of the apparatus main body.

(8) A rotatable first roller having a heating source, a second roller which rotates while being in pressure contact with the first roller, and a guide member which constitutes a sheet conveying path above the second roller. An image forming apparatus comprising a roller-type fixing device comprising:

(9) The image forming apparatus according to (8), wherein the guide member is rotatable about one end as a fulcrum.

(10) A rotatable first roller having a heating source, a second roller which rotates while being in pressure contact with the first roller, and a rotating member which constitutes a sheet conveying path above the second roller. A movable guide member, and a roller-type fixing device configured to release pressure contact between the first roller and the second roller by rotating the guide member. Image forming apparatus.

(11) A rotatable first roller having a heating source, a second roller which rotates while being pressed against the first roller, and an urging member which urges the second roller toward the first roller. A member, a rotatable guide member provided at a position above the second roller and constituting a sheet conveying path, a holding member for holding the second roller and rotatable about a fulcrum, and the guide A pressing arm for transmitting a rotational force of a member to the holding member, and separating the second roller from the first roller via the pressing arm and the holding member when the guide member rotates. An image forming apparatus comprising:

(12) The image forming apparatus according to (11), wherein the pressing arm is a part of the holding member.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing a configuration of a digital image forming apparatus 1, and FIG. 2 is a schematic diagram of the image forming apparatus showing a portion (range) provided integrally with an opening / closing door.

In FIG. 1, the image forming apparatus 1 includes an automatic document feeder (ADF) A, a document image reading section B for reading an image of a document fed by the automatic document feeder, and a read document. An image control board C for processing an image, a writing section D including a writing unit 12 for writing on an image carrier 10 made of a photosensitive drum in accordance with data after the image processing, and a charge electrode on the image carrier 10 and the periphery thereof 14, an image forming section E including image forming means such as a developing means 16 including a magnetic brush type developing device, a transfer electrode 18, a separation electrode 20, and a cleaning means 21, and a sheet (image forming paper) P made of plain paper. A storage section F is provided for a plurality of paper storage means (hereinafter, referred to as a paper feed tray or simply a tray) 22, 24 such as a tray for storing.

The automatic document feeder A includes a document table 2
6, and a document transport processing unit 28 including a roller group including the roller R1 and a switching means (without reference symbols) for appropriately switching a document moving path, etc., as main components.

The original image reading section B is located below the top glass G and can move back and forth while maintaining the optical path length, a fixed imaging lens (hereinafter simply referred to as a lens) 33, and a line. Image sensor (hereinafter C
The writing section D includes a laser light source 40, a polygon mirror (polarizer) 42, and the like.

The automatic document feeder A has a difference in configuration from a conventional automatic document feeder, but the principle itself is well known, and the original reading section B, writing section D,
Since an image forming apparatus and an image forming process including an image processing unit and an image forming unit (a unit that forms a toner image on the image carrier 10 and transfers the toner image onto a sheet) are well known, The description of that side will be simplified.

When viewed from the moving direction of the sheet P, R10 shown on the front side of the transfer electrode 18 is a registration roller, and the roller side fixing device (hereinafter simply referred to as R10) is shown on the downstream side of the separation electrode 20. Fixing device)
3.

In the embodiment, the main components of the fixing device 3 are a heating roller having a built-in heating source and a pressure roller (pressure roller) which rotates while being pressed against the heating roller. The details will be described later. I do.

The fixing device 3 is a cleaning means for cleaning the heating roller, and is constituted by a cleaning web which can be wound up.

The transfer electrode 18 and the separation electrode 2
Numeral 0 is provided on one support member 17, and the support member 17 is rotatable clockwise around a part of the lower end thereof as a fulcrum.

The rotation range of the transfer / separation unit is fixedly controlled by at least two stages of rotation angles, in which a minimum space is created for handling jams and a large space is created for maintenance by a serviceman. It is configured as follows.

Hereinafter, when a structure composed of the transfer electrode 18, the separation electrode 20, and the support member 17 having the above configuration is expressed, it is referred to as a transfer separation unit Y (see FIG. 3).

In the above configuration, a process of forming a toner image on the image carrier 10, transferring the toner image onto a sheet, and then discharging the toner image to a paper discharge tray is as follows.

In the present specification, including this section, the transfer area where the transfer electrode 18 is located may be referred to as an image forming section.

One of the originals (not shown) placed on the original placing table 26 is transported in the original transport processing unit 28, and the slit exposure by the exposure means L is performed while passing under the roller R1. Done.

The reflected light from the original passes through the mirror units 30 and 31 and the lens 33 at fixed positions to form an image on the CCD and is read.

The image information read by the document image reading section B is processed by an image processing means, encoded, and stored in a memory provided on the image control board C.

The image data is called in accordance with the image formation, and the laser light source 40 in the writing section D is driven in accordance with the image data, and the image carrier 1 is driven.
Exposure is performed on 0.

Prior to the exposure, the image carrier 10 that rotates in the direction of the arrow (counterclockwise) is attached to the charging electrode 14.
A predetermined surface potential is applied by the corona discharge action of the above, but the exposure reduces the potential of the exposed portion in accordance with the amount of exposure, and as a result, an electrostatic latent image corresponding to the image data is formed on the image carrier 10. Formed on top.

The electrostatic latent image is reversely developed by the developing means 16 to be a visible image (toner image).

On the other hand, before the leading end of the toner image on the image carrier 10 reaches the transfer area, for example, one sheet P in the paper feed tray 22 is fed and conveyed to the registration roller R10. And is regulated at the tip.

The sheet P is conveyed toward the transfer area by the registration roller R10, which starts rotating in synchronization with the toner image, that is, the image area on the image carrier 10, so as to overlap.

In the transfer area, the toner image on the image carrier 10 is transferred onto the sheet P by the urging of the transfer electrode 18, and then the sheet P is urged by the separation electrode 20. Separated from 10.

Thereafter, the toner powder for forming the toner image is melted and fixed on the sheet P by the pressurizing and heating action in the fixing device 3. Is discharged onto the discharge tray T via the.

Returning to FIG. 1, the sheet P is shown only on the paper feed tray 22. Reference symbol S in the paper feed tray 24 is a movable plate whose free end is always urged upward by an urging means such as a coil spring (not shown).
As a result, the uppermost sheet comes into contact with a delivery roller described later.

The paper feed tray 22 also has the same configuration as that described above. In the embodiment, the paper feed trays 22 and 24 are arranged in two stages in the vertical direction, but may be provided with more paper feed trays.

Of the sheet feeding trays, the lower stage (in the embodiment, the sheet feeding tray is a two-stage stack, so the lower stage is used.
A space 25 having a predetermined gap is formed between the bottom (same as the bottom wall) of the paper feed tray 24 arranged at the lowermost position) and the bottom wall of the apparatus main body.

The space 25 is used in a mode (mode) in which images are formed on both sides of the sheet P, and is cooperated with a second transport path 80 (described later) for reversing the sheet front and back. Helps achieve reversal.

Reference numerals 50 and 53 above the leading ends (corresponding to the leading ends of the sheets P stored in the sheet feeding direction) of the sheet feeding trays 22 and 24 indicate sheet feeding means (hereinafter referred to as feed-out means) comprising rollers. Roller), 51 and 5
4 is a feed roller, and 52 and 55 are double feed prevention rollers.

The paper feeder according to the present invention basically includes the above-mentioned feed roller, feed roller, and double feed prevention roller. Hereinafter, this configuration will be expressed as a paper feeder K.

In FIG. 1 and FIG. 2, the reference symbol K of the paper feeder is omitted because of congestion (see FIG. 3).

The paper feeder corresponding to the paper feed tray 22 is called K1, the paper feeder corresponding to the paper feed tray 24 is called K2, and the paper feeder corresponding to the manual paper feed tray is called K3. If not, it is simply referred to as a paper feeder K.

In the paper feeder K, the feed rollers (50, 53) and the feed rollers (51, 54) are unitized (hereinafter, this unit is simply referred to as a roller unit). Has a configuration that can be easily attached to and detached from a driving shaft connected to a driving source provided in the printer or a locking means provided in a paper feeding unit.

The double feed prevention rollers (52, 55)
Is also unitized (hereinafter, when this unit is expressed, referred to as a double feed prevention roller unit), and has a configuration that can be easily attached to and detached from a fixing member provided on a fixing portion of the apparatus main body.

Reference numeral 60 denotes a manual paper feed tray attached to the manual paper feed unit, which can be opened and closed with the lower end as a fulcrum with respect to the main body side wall of the image forming apparatus 1.

Reference numeral 61 denotes a paper feeding means (hereinafter, referred to as a feeding roller) comprising rollers for feeding out a sheet placed on the manual paper feeding tray 60 with image formation;
Reference numeral 3 denotes a feed roller provided downstream of the feed roller 61, and reference numeral 65 denotes a double feed prevention roller for pressing the feed roller 63 to prevent a plurality of sheets P from being fed. Have substantially the same configuration to fulfill the same function as the sheet feeding device K provided corresponding to.

Reference numeral 66 denotes a conveyance path for the sheet P sent from the manual feed tray 60, which communicates with a junction 76 described later via a pair of conveyance rollers R15 shown immediately to the left of the feed roller 63.

Reference numeral 70 denotes a first transport path for forming an image on the sheet P by transfer, and extends upward from below when viewed in the moving direction of the sheet fed from the appropriate paper feed tray. I have.

Reference numeral 72 denotes a sheet feeding path for sheets stored in the upper sheet feeding tray 22; 74, a sheet feeding path for sheets stored in the lower sheet feeding tray 24; This is a merging section (a part of the first conveyance path 70) where the sheets P sent from the sheet 24 merge.

Reference numeral 78 denotes a paper discharge path for discharging the sheet P on which a predetermined image has been formed onto the paper discharge tray T.

Reference numeral 80 denotes a second conveyance path for reversing the front and back of a sheet used for forming an image on both sides of the sheet.
The upper part of the figure communicates with the first transport path.

As will be described later, the lower guide member of the upper arc-shaped guide portion of the second transport path 80 is provided integrally with the fixing device 3, and it is necessary to separate the pressure roller from the heating roller. When it occurs, it is used as an operating member of the separating mechanism.

The second conveying path 80 extends from above to below when viewed from the moving direction of the sheet.

The lower end of the second conveying path 80 is a conveying path extending substantially vertically, and the lower end thereof is lower than the sheet feeding section of the lower sheet feeding tray 24 (the position of the sheet feeding device K2). Side, and is connected (communicated) with the first transport path 70.

As can be understood from the above description, the first transport path 70 and the second transport path 80 form a longitudinally long loop on one side wall of the apparatus main body.

Most of the one guide portion (guide member) constituting the second conveyance path 80 is provided integrally with the opening / closing door 5 described later.

A part of the first transport path 70 cooperates with a part of a guide member (guide portion) forming the second transport path, and a part of the second transport path 80 is Each transport path is formed in cooperation with a part of a guide member (guide portion) constituting one transport path 70.

The first transport path 70 and the second transport path 80
Is provided with a transport unit R20 (hereinafter, referred to as a switchback roller R20 for convenience of description) including a pair of reversible rollers.

Since the connection portion is not one in which the sheet P is continuously conveyed from the second conveyance path 80 to the first conveyance path 70, it can be said that the connection portion is a branching section that separates the two conveyance paths.

Below the switchback roller R20, a passage leading to the space 25 is provided, and when the sheet P is turned upside down, the sheet P moving on the second transport path 80 is moved to the space. It is used to face the part 25.

In the image forming process, when the sheet P moving along the second conveying path 80 is sent out toward the space 25, the rear end of the sheet P is gripped by the switchback roller R20. Therefore, a part of the sheet is stored in the space 25.

Reference numeral 90 denotes an (upper) branch guide, which is controlled so as to direct the sheet P, on which an image has been formed on the first surface, to the paper discharge path 78 or to the second transport path 80. You.

In other words, it is controlled in accordance with the image forming mode set by the user (mode for forming an image on only one side of a sheet or mode for forming an image on both sides of a sheet),
Switch the sheet conveyance path.

For example, when the mode for forming an image on both sides of the sheet is set, the branch guide 90 transfers the sheet P, which has been formed on the first side and has a transfer toner image, to the second conveying section. The sheet is fed to the path 80 at a broken line position in the figure, and after the sheet is fed to the second conveyance path 80, the sheet is controlled via a control unit (not shown) so as to take a solid line position in the figure.

The members located on the first transport path 70 and the second transport path 80 and indicated by a pair of circles (without reference symbols) are transport rollers.

The image forming process for the second side of the sheet in the image forming apparatus having the above configuration is as follows.

As described above, when the sheet P on which the image is formed on the first surface moves up the first transport path 70 and the leading end reaches the branch guide 90, the branch guide 90
Since the sheet P is maintained at the position indicated by the broken line in the figure, the sheet P enters the second conveyance path 80 and continues to move.

The entrance portion of the second transport path 80 has a gentle arc, and ensures smooth movement of the sheet P.

When the sheet P is moved down the second conveying path 80 and reaches the lower end thereof, the sheet P is nipped by the switchback roller R20, conveyed downward from the second conveying path, and fed to the lower stage. It is guided to the space 25 formed below the tray 24.

At this time, the first image formed on the sheet P
The surface is facing down. Eventually, when the switchback roller R20 stops rotating while holding the rear end of the sheet P, and then starts rotating in the opposite direction, the sheet P is turned upside down, that is, The second surface on which an image is not formed is fed into the first transport path 70 with the second surface facing the image carrier 10, and is regulated by the registration roller R <b> 10.

On the other hand, a second toner image is formed on the image carrier 10 by the above-described process, and the registration roller R is synchronized with the rotation of the image carrier 10.
When the rotation of the sheet P starts, the sheet P enters the transfer area while overlapping with the second toner image area.

Thereafter, when the leading end of the sheet P subjected to the transfer processing, the separation processing, and the fixing processing reaches a certain portion of the branch guide 90, the branch guide 90 is kept at the position indicated by the solid line in FIG. Since the first conveyance path 70 and the paper discharge path 78 are in communication with each other and the communication with the second conveyance path 80 is cut off, the sheet P enters the paper discharge path 78 and is discharged by the paper discharge roller. The sheet is discharged onto the sheet discharge tray T via the line 79.

By the way, as for the manual paper feed tray 60 provided in the manual paper feed section, in the embodiment, as shown in FIG. 2, the outer side surface is formed with a side wall forming a part of the outer shape of the apparatus main body. Provided on the opening / closing door 5.

Also, including the manual paper feed tray 60,
The sheet feeding device K3 that handles sheets placed thereon is
It is attached to the opening / closing door at substantially the same height position as the sheet feeding device K1 for the sheet feeding tray 22.

Further, one guide member (hereinafter referred to as a ninth guide member for convenience) 5 forming the second transport path 80 is provided.
Numeral 05 is formed by using the inside of the opening / closing door 5, and this configuration has an effect that it is not necessary to provide a special structure at a portion intersecting with the transport path 66.

Further, the feed roller 63 and the double feed prevention roller 65 constituting the sheet feeding device K3 and the second conveying path 8
Since the distance between the pair of conveying rollers R15 provided across the line 0 can be shortened, the sheet P can be surely conveyed.

The guide surface 505 may be obtained by integral molding with the door 5, or may be obtained by integrally forming an appropriate plate or molded product with the door 5.

It is desirable that the inclination of the conveyance path 66 should be as straight as possible so as not to apply an unnecessary load to the sheet.

In FIG. 2, a region shown by a two-dot chain line is a diagram schematically showing a region provided integrally with the door 5 as described above.

The opening / closing door 5 has a sheet feeding device K3 of the manual sheet feeding section and most of one guide member forming the second conveyance path 80, and one guide surface of the first conveyance path 70. The guide member is provided integrally.

The opening / closing door 5 is configured to be rotatable by 90 degrees in the horizontal direction with respect to the fixing portion of the apparatus main body. In the embodiment, the opening and closing door 5 is configured to be rotatable around the back side in the drawing. I have.

In the above configuration, the sheet conveyance path can be largely opened, so that the jam processing is easy. By the way, with respect to image formation using a sheet placed on the manual sheet feeding unit or the manual sheet feeding tray 60, a conveyance route until the leading end is regulated by the registration roller R10 uses another sheet feeding tray. The image forming process after that is the same as that described above, except for the point that the image forming process is performed.

FIG. 3 is a schematic diagram showing the periphery of the first transport path 70 and the second transport path 80 when the door 5 is closed. FIG. 4 shows the state when the door 5 is opened. 3 is a schematic view showing the rotation of the guide member according to the present invention, wherein the opening / closing door is shown with a 90 ° phase shift.

However, the upper part of the first conveyance path 70 is omitted from the drawing because it is constituted by the fixing device 3.

In the drawings, the same members as those described above are denoted by the same reference symbols, and redundant description will be omitted.

The guide member constituting the first conveying path 70 and provided on the apparatus main body side is a sheet P
When viewed from the moving direction, the first guide member 700, the fixed second guide member 710 having a guide surface inclined upward and to the left via the conveyance roller pair R7, and the sheet conveyed along the second guide member are substantially described. A third guide member 720 for directing directly above and a pair of guide members (fourth guide member) 730 fixed and provided directly above the third guide member 720.

The guide member on the other side positioned opposite to the guide member on the one side is provided integrally with the door 3.

That is, it has a fixed fifth guide member 515 that partially faces the first guide member 700 and extends substantially linearly in the vertical direction, and a rear surface that is inclined to the upper left and faces the first guide member 700. The sixth guide member 520, the seventh guide member 525 having a surface facing the second guide member 710, and the eighth guide member 530 having a plane facing the third guide member 720 are the same.

When viewed from the moving direction of the sheet P, the second conveyance path extends vertically following the semicircular upper guide surface 510 and further gently slopes to the lower left with a ninth guide member 505. Tenth guide member 535 and eleventh guide member 54 provided on an extension of the ninth guide member
0, a twelfth guide member 545 having a surface opposed to the tenth and eleventh guide members, and an eighth guide member 530, a seventh guide member 525, and a thirteenth guide member inclined downward and to the lower right opposite thereto. One surface of the guide member 550, the sixth guide member 520, and the fifth guide member 5
15 and the like.

Reference numeral 501 denotes a resin molded product having the ninth guide member 505, which is integrated with the inside of the side wall with a screw or the like.

The back surface of the support member 17 forms a second transport path in cooperation with the ninth guide member 505.

As shown by a two-dot chain line in FIG. 4, the first guide member 700
20 can be rotated clockwise about the axis 20.
The guide member 525 is configured to be rotatable counterclockwise about a position below the transport roller R6 as a fulcrum.

In the figure, the first guide member 700
In FIG. 1, the sheet sent from the paper feed tray 24 in FIG. 1 is disposed immediately before reaching the junction with the first transport path 70, and the guide member 700 and the seventh
The guide member 525 is a tunnel-shaped guide.

The length of the guide portion is longer than the length of the minimum size (for example, B5 size) sheet to be used in the transport direction.

Therefore, if the sheet is jammed here, it will not be visible even if the door is opened, and it will take time to find the location of the jam as described above.

Thus, in the embodiment, the first
The above problem was solved by forming the guide member 700 and the seventh guide member 525 from transparent resin.

With such a simple configuration, it is possible to expect an effect that the number of sheet detecting means provided at an appropriate position on the conveyance path can be reduced, for example.

FIGS. 5 and 6 show that the transfer / separation unit Y is rotated in two stages, and FIG. 5 shows a state where a preset first stage rotation angle is given. FIG. 6 is a diagram showing a state where a preset second-stage rotation angle is given.

In the figure, reference numeral 170 denotes a finger hook provided on the support member 17 constituting the transfer / separation unit Y;
Is a shaft that rotatably holds the transfer unit Y,
810 is a first stopper provided at a fixed position of the apparatus main body.

The stoppers 810 are detachably provided on both sides of the transfer separation unit Y so as to be in contact with both side walls (rear surface).

When a jam occurs in a region sandwiched between the transfer / separation unit Y and the image carrier 10, the operator opens the opening / closing door 5 and rotates the transfer / separation unit Y clockwise to support the support member. 17 and the first stopper 81
After releasing the hand at the point where the abutment with the abutment 0 comes in contact, the jammed sheet is removed, and the transfer / separation unit Y is rotated and returned in the opposite direction.

The position of the transfer / separation unit Y at the time of rotation return can be fixed by a known lock mechanism or the like.

In the embodiment, the rotation angle (opening angle) is set to approximately 50 °, but may be set to a larger angle depending on the surrounding configuration or the degree of influence of the photosensitive layer on light.

When a space that is more open than the first rotation angle is required, such as for maintenance by a serviceman, the first stopper 810 is removed, and the transfer separation unit Y is rotated while being held. If both side walls of the support member 17 are brought into contact with the second stopper 820, the support member 17 can be opened by about 90 °.

As described above, in the case of jam processing, the transfer separation unit is fixed at the minimum rotation angle, and a large rotation angle is provided only when a large space is required. Even if the frequency of the jam processing in the area is high, the adverse effect on the image carrier can be suppressed, and a large space can be formed when necessary, so that the operability is good.

In other words, particularly in the embodiment,
The structure exposes the width of the image carrier (length in the direction from the front to the back in the figure), and the portion exposed to light is more likely to be adversely affected than the remaining portion, but this is covered as much as possible. be able to.

FIG. 7 is a schematic diagram showing the structure of the fixing device 3, and FIG. 8 is a schematic diagram showing a state in which a gap is formed between the rollers at the time of jam processing or the like.

In the figure, reference numeral 300 denotes a heating roller (first roller) containing a heating source (not shown), which is provided rotatable counterclockwise at a fixed position.

Reference numeral 305 denotes a pressure roller (second roller) which rotates while pressing (pressing) the heating roller 300.

Reference numeral 310 denotes a holding member,
5 functions as an intermediate member when pressing the heating roller 300 against the heating roller 300 or separating the heating roller 5 from the heating roller 300, and is configured to be rotatable around a shaft 320 as a fulcrum.

In other words, the holding member 310 allows the rotation of the pressure roller 305, and rotates the pressure roller about the shaft 320 through its own rotation.

The position of the shaft 320 is slightly located on the heating roller 300 side with respect to the virtual horizontal line when a perpendicular line passing through the center of the pressure roller 305 is drawn with respect to the virtual horizontal line.

315 is a pressing arm provided integrally with the holding member. Reference numeral 330 denotes a lower guide member having an arc-shaped portion positioned to face the upper arc-shaped guide portion of the second conveyance path 80 when the fixing device 3 is mounted at a predetermined position of the device. Is configured to be used also as an operation member for bringing the pressure roller 305 into and out of contact with the heating roller 300, and is positioned above the pressure roller 305.

As the operation member, the guide member 3
30 and another member can be facilitated.

The guide member 330 is made of a heat-resistant resin molded product, and is integrally formed with a support 340 that can rotate about a shaft 335 as a fulcrum.

The lower end of the support 340 faces the pressing arm 315, and is related to apply a predetermined pressing force to the pressing arm during rotation.

Reference numeral 345 denotes an urging member constituted by a spring.
Is urged in a direction in which it is pressed against the heating roller 300.

Reference numeral 333 denotes a guide member located below the guide member 330 and facing the ninth guide member to constitute a part of the second transport path.

The guide member 333 is connected to the fixing device 3.
Although the outer frame is used, another member may be integrally formed.

Reference numeral 355 denotes a guide member provided on the substrate of the fixing device, and reference numeral 360 denotes a cleaning means for cleaning the surface of the heating roller 300, and a cleaning web as a main element.

When a sheet is jammed in the fixing device 3 having the above configuration, as shown in FIG. 8, the opening / closing door 5 is opened, a gap is formed between both rollers via the holding member 310, and Removal will be performed.

That is, when the guide member 330 is rotated clockwise from the state shown in FIG. 7, the lower end of the support 340 functions as a cam member and the pressing arm 315
Then, a pressing force against the urging force of the urging member 345 is applied to the pressing arm 315.

In other words, the pressing arm 315 receives the pressing force rotating clockwise about the shaft 320 and rotates clockwise together with the holding member 310 which is integrally formed.

When the holding member 310 is rotated, the pressure roller 305 provided so as to be integrally movable with the holding member is rotated about a shaft 320 as a fulcrum.

The above operation will be described later.
The pressing state between the pressure roller 0 and the pressing roller 305 is released, and a gap is formed between both rollers.

In the above-described gap forming state, the jam processing is performed. In the present embodiment, since the transfer separation unit Y is provided immediately below the fixing device 3, the pressure separation is performed after the transfer separation unit Y is opened to the first stage rotation angle. Thereby, easy and quick jam processing can be performed.

Further, the mechanism for separating the two rollers only needs to have a simple structure in which the guide member is tilted down as an operation member.

Further, since a guide member constituting the sheet conveying path is provided as a part of the fixing device 3, the mechanism around the guide member can be simplified and the device can be expected to be more compact.

For locking the guide member at the normal position, a known lock mechanism may be employed, or no special lock mechanism may be provided by utilizing the urging force of the urging member applied to the pressing arm. It may be configured.

[0146]

According to the present invention, it is possible to easily perform a jam processing with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a digital image forming apparatus.

FIG. 2 is a schematic diagram of the image forming apparatus showing a portion (range) provided integrally with the door.

FIG. 3 is a schematic diagram illustrating the periphery of a first transport path and a second transport path when the door is closed.

FIG. 4 is a schematic diagram showing rotation of a guide member according to the present invention when the door is opened.

FIG. 5 is a diagram showing a state in which a preset first stage rotation angle is given to a transfer separation unit.

FIG. 6 is a diagram illustrating a state in which a preset second stage rotation angle is given to the transfer separation unit.

FIG. 7 is a schematic diagram illustrating a configuration of a fixing device.

FIG. 8 is a schematic diagram showing a state in which a gap is formed between rollers at the time of jam clearance or the like.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 image forming device 3 fixing device 5 door 10 image carrier 17 support member 70 first transport path 80 second transport path 300 heating roller 305 pressure roller 310 holding member 330 guide member 340 support member 345 biasing member 525 seventh guide Member 700 First guide member

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/20 107 G03G 15/20 107 3F101 (72) Inventor Saburo Shimizu 2970, Ishikawacho, Hachioji City, Tokyo Inside the Company (72) Kunihiro Kawachi Konica Corporation, 2970 Ishikawa-cho, Hachioji-shi, Tokyo Inside the Company (72) Inventor Hiroyasu Sato, 2970 Ishikawa-cho, Ishikawa-cho, Hachioji-shi, Tokyo Inside the Konica Corporation (72) Inventor Hideo Isohara Tokyo 2970 Ishikawa-cho, Hachioji-shi Konica Corporation F-term (reference) FB05 FD02 FE02 FE08 LA02 LA05 LA07 LB03

Claims (12)

[Claims] 1. An image forming apparatus for transferring a toner image formed on an image carrier onto a sheet and fixing the toner image to form an image, wherein a part of a guide member forming a sheet conveying path is formed of a transparent resin, An image forming apparatus, which is provided so as to be openable and closable. 2. The method according to claim 1, wherein the first toner image formed on the image carrier is transferred onto one surface of a sheet conveyed along the first conveyance path, and is fixed. Then, the sheet is turned over via the second conveyance path. And then re-sending the sheet to the first conveyance path to transfer and fix the second toner image on the other surface of the sheet to form an image, wherein the first conveyance path or the second conveyance path An image forming apparatus characterized in that a part of the guide member that constitutes (1) is made of a transparent resin and disposed so as to be openable and closable. 3. The image forming apparatus according to claim 1, wherein the opening / closing is a rotation about one end as a fulcrum. 4. A part of the first conveyance path cooperates with a part of a guide member forming the second conveyance path, and a part of the second conveyance path cooperates with the first conveyance path. 3. The image forming apparatus according to claim 2, wherein each of the conveying paths is formed in cooperation with a part of the guide member to be formed. 5. The apparatus according to claim 2, wherein at least one of the guide members forming the second transport path is provided integrally with an opening / closing door provided on a side surface of the apparatus main body. The image forming apparatus according to claim 1. 6. An image forming apparatus having a transfer / separation unit provided to face an image carrier, wherein said transfer / separation unit is rotatably provided with one end as a fulcrum, and at least two stages of rotation angles. An image forming apparatus comprising: an image forming apparatus; 7. The image forming apparatus according to claim 6, wherein the transfer / separation unit is configured to be exposed by opening an opening / closing door provided on a side surface of the apparatus main body. 8. A rotatable first roller having a heating source, a second roller rotating while being pressed against the first roller, and a guide member forming a sheet conveying path at a position above the second roller. An image forming apparatus comprising a roller-type fixing device comprising: 9. The image forming apparatus according to claim 8, wherein the guide member is rotatable about one end as a fulcrum. 10. A rotatable first roller having a heating source, a second roller that rotates while being in pressure contact with the first roller, and a rotation that constitutes a sheet conveying path above the second roller. And a roller-type fixing device configured to release pressure contact between the first roller and the second roller by rotating the guide member. Image forming apparatus. 11. A rotatable first roller having a heating source, a second roller rotating while being pressed against the first roller, and an urging member for urging the second roller toward the first roller. A rotatable guide member provided at an upper position of the second roller and forming a sheet conveyance path; a holding member that holds the second roller and can rotate about a fulcrum; and the guide member. And a pressing arm for transmitting the turning power of the second roller to the holding member. When the guide member rotates, the second roller is separated from the first roller via the pressing arm and the holding member. An image forming apparatus comprising: 12. The image forming apparatus according to claim 11, wherein the pressing arm is a part of the holding member.